Organic light-emitting device

ABSTRACT

An organic light-emitting device including a first electrode, a second electrode facing the first electrode, and an organic layer disposed between the first electrode and the second electrode, wherein the organic layer includes an emission layer and an intermediate layer disposed between the first electrode and the emission layer, wherein the intermediate layer directly contacts the emission layer, and wherein the intermediate layer includes a first hole transport material, wherein the emission layer includes a host and a dopant, wherein the dopant is an organometallic compound, provided that the dopant does not comprise iridium, and wherein the organic light-emitting device satisfies certain parameters described in the specification.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Korean Patent Application No.10-2017-0084409, filed on Jul. 3, 2017, in the Korean IntellectualProperty Office, and all the benefits accruing therefrom under 35 U.S.C.§ 119, the content of which is incorporated herein in its entirety byreference.

BACKGROUND 1. Field

One or more embodiments relate to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices (OLEDs) are self-emission devices, whichhave superior characteristics in terms of a viewing angle, a responsetime, a brightness, a driving voltage, and a response speed, and whichproduce full-color images.

In an example, an organic light-emitting device includes an anode, acathode, and an organic layer that is disposed between the anode and thecathode, wherein the organic layer includes an emission layer. A holetransport region may be disposed between the anode and the emissionlayer, and an electron transport region may be disposed between theemission layer and the cathode. Holes provided from the anode may movetoward the emission layer through the hole transport region, andelectrons provided from the cathode may move toward the emission layerthrough the electron transport region. The holes and the electronsrecombine in the emission layer to produce excitons. These excitonstransit from an excited state to a ground state, thereby generatinglight.

Various types of organic light emitting devices are known. However,there still remains a need in OLEDs having low driving voltage, highefficiency, high brightness, and long lifespan.

SUMMARY

Aspects of the present disclosure provide an organic light-emittingdevice that satisfies certain parameters, includes an iridium-freeorganometallic compound, and has high luminescent efficiency and a longlifespan.

Additional aspects will be set forth in part in the description whichfollows and, in part, will be apparent from the description, or may belearned by practice of the presented embodiments.

An aspect provides an organic light-emitting device including:

a first electrode;

a second electrode facing the first electrode; and

an organic layer disposed between the first electrode and the secondelectrode,

wherein the organic layer includes an emission layer, and anintermediate layer disposed between the first electrode and the emissionlayer,

the intermediate layer directly contacts the emission layer and includesa first hole transport material,

the emission layer includes a host and a dopant,

the dopant is an organometallic compound, provided that the dopant doesnot include iridium, and

the organic light-emitting device satisfies a condition ofHOMO(h1)−HOMO(host)<0 electron volts,

wherein HOMO(h1) indicates the highest occupied molecular orbital (HOMO)energy level (expressed in electron volts) of the first hole transportmaterial,

i) when the host consists of a single host, the HOMO(host) indicates aHOMO energy level (expressed in electron volts) of the single host andii) when the host is a mixture of two or more different hosts, theHOMO(host) indicates the highest energy level among HOMO energy levels(expressed in electron volts) of the two or more different hosts, and

HOMO(h1) and HOMO(host) are measured by using a photoelectronspectrometer (e.g., AC3 manufactured by RIKEN KEIKI Co., Ltd) in anambient atmosphere.

The organic light-emitting device may satisfy a condition ofHOMO(dopant)−HOMO(host)<0.40 electron volts,

wherein HOMO(dopant) is a HOMO energy level (expressed in electronvolts) of the dopant included in the emission layer, and

HOMO(dopant) may be measured by using a photoelectron spectrometer in anambient atmosphere.

The organic light-emitting device may further include a hole transportregion disposed between the first electrode and the intermediate layer,

the hole transport region may include a second hole transport material,and

the organic light-emitting device may satisfy a condition ofHOMO(h1)−HOMO(h2)<0 electron volts,

wherein HOMO(h2) is a HOMO energy level of the second hole transportmaterial, and HOMO(h2) may be measured by using a photoelectronspectrometer.

Another aspect provides an organic light-emitting device including:

a first electrode;

a second electrode facing the first electrode;

light-emitting units in the number of m, stacked between the firstelectrode and the second electrode and including at least one emissionlayer; and

charge-generation layers in the number of m−1, disposed between twoneighboring light-emitting units selected from the light-emitting unitsin the number of m and including an n-type charge-generation layer and ap-type charge-generation layer,

wherein m is an integer greater than or equal to 2,

a maximum emission wavelength of light emitted by at least one of thelight-emitting units in the number of m is different from a maximumemission wavelength of light emitted by at least one of the otherlight-emitting units,

at least one of the light-emitting units in the number of m includes atleast one intermediate layer that is located at a side closer to thefirst electrode, directly contacts the emission layer, and includes afirst hole transport material,

the emission layer includes a host and a dopant,

the dopant is an organometallic compound, provided that the dopant doesnot include iridium, and

the organic light-emitting device satisfies a condition ofHOMO(h1)−HOMO(host)<0 electron volts,

wherein HOMO(h1) indicates a HOMO energy level (expressed in electronvolts) of the first hole transport material,

i) when the host consists of a single host, the HOMO(host) indicates aHOMO energy level (expressed in electron volts) of the single host andii) when the host is a mixture of two or more different hosts, theHOMO(host) indicates the highest energy level among HOMO energy levels(expressed in electron volts) of the two or more different hosts, and

HOMO(h1) and HOMO(host) are measured by a photoelectron spectrometer(e.g., AC3, manufactured by RIKEN KEIKI Co., Ltd) in an ambientatmosphere.

Another aspect provides an organic light-emitting device including:

a first electrode;

a second electrode facing the first electrode; and

emission layers in the number of m, stacked between the first electrodeand the second electrode,

wherein m is an integer greater than or equal to 2,

a maximum emission wavelength of light emitted by at least one of theemission layers in the number of m is different from a maximum emissionwavelength of light emitted by at least one of the other emissionlayers,

at least one intermediate layer that directly contacts at least one ofthe emission layers and includes a first hole transport material isdisposed between the emission layers in the number of m and the firstelectrode,

the emission layers each include a host and a dopant,

the dopant is an organometallic compound, provided that the dopant doesnot include iridium, and

the organic light-emitting device satisfies a condition ofHOMO(h1)−HOMO(host)<0 electron volts,

wherein HOMO(h1) indicates a HOMO energy level (expressed in electronvolts) of the first hole transport material,

i) when the host consists of a single host, the HOMO(host) indicates aHOMO energy level (expressed in electron volts) of the single host andii) when the host is a mixture of two or more different hosts, theHOMO(host) indicates the highest energy level among HOMO energy levels(expressed in electron volts) of the two or more different hosts, and

HOMO(h1) and HOMO(host) are measured by a photoelectron spectrometer(e.g., AC3 manufactured by RIKEN KEIKI Co., Ltd) in an ambientatmosphere.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of an organic light-emitting device accordingto an embodiment;

FIG. 2 is a diagram showing HOMO(h2), HOMO(h1), HOMO(host), andHOMO(dopant) of an organic light-emitting device;

FIG. 3 is a schematic view of an organic light-emitting device accordingto an embodiment;

FIG. 4 is a schematic view of an organic light-emitting device accordingto an embodiment;

FIG. 5 is a graph of luminance (candelas per square meter, cd/m²) versusexternal quantum efficiency (percent, %) of organic light-emittingdevices manufactured according to Comparative Example A, ComparativeExample B, Example 1, and Example 2;

FIG. 6 is a graph of time (hours, hr) versus luminance (candelas persquare meter, cd/m²) of organic light-emitting devices manufacturedaccording to Comparative Example A, Comparative Example B, Example 1,and Example 2;

FIG. 7 is a graph of time (hours, hr) versus luminance (candelas persquare meter, cd/m²) of organic light-emitting devices manufacturedaccording to Comparative Example C and Comparative Example D; and

FIG. 8 is a graph of time (hours, hr) versus luminance (candelas persquare meter, cd/m²) of organic light-emitting devices manufacturedaccording to Comparative Example E and Example 3.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to like elements throughout. In this regard, the presentembodiments may have different forms and should not be construed asbeing limited to the descriptions set forth herein. Accordingly, theembodiments are merely described below, by referring to the figures, toexplain aspects of the present disclosure. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items. Expressions such as “at least one of,” whenpreceding a list of elements, modify the entire list of elements and donot modify the individual elements of the list.

It will be understood that when an element is referred to as being “on”another element, it can be directly in contact with the other element orintervening elements may be present therebetween. In contrast, when anelement is referred to as being “directly on” another element, there areno intervening elements present.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer, orsection from another element, component, region, layer, or section.Thus, a first element, component, region, layer, or section discussedbelow could be termed a second element, component, region, layer, orsection without departing from the teachings of the present embodiments.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

The term “or” means “and/or.” It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this general inventive conceptbelongs. It will be further understood that terms, such as those definedin commonly used dictionaries, should be interpreted as having a meaningthat is consistent with their meaning in the context of the relevant artand the present disclosure, and will not be interpreted in an idealizedor overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

“About” or “approximately” as used herein is inclusive of the statedvalue and means within an acceptable range of deviation for theparticular value as determined by one of ordinary skill in the art,considering the measurement in question and the error associated withmeasurement of the particular quantity (i.e., the limitations of themeasurement system). For example, “about” can mean within one or morestandard deviations, or within ±30%, 20%, 10%, 5% of the stated value.

Description of FIGS. 1 and 2

In FIG. 1, an organic light-emitting device 10 includes a firstelectrode 11, a second electrode 19 facing the first electrode 11, andan organic layer 10A disposed between the first electrode 11 and thesecond electrode 19.

In FIG. 1, a substrate may be additionally disposed under the firstelectrode 11 or above the second electrode 19. The substrate may be aglass substrate or a plastic substrate, each having excellent mechanicalstrength, thermal stability, transparency, surface smoothness, ease ofhandling, and water resistance.

First Electrode 11

The first electrode 11 may be formed by depositing or sputtering amaterial for forming the first electrode 11 on the substrate. When thefirst electrode 11 is an anode, the material for forming a firstelectrode may be selected from materials with a high work function tofacilitate hole injection.

The first electrode 11 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 11 is a transmissive electrode, a material for forming a firstelectrode may be selected from indium tin oxide (ITO), indium zinc oxide(IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinations thereof,but embodiments of the present disclosure are not limited thereto. Whenthe first electrode 110 is a semi-transmissive electrode or a reflectiveelectrode, as a material for forming the first electrode 110, magnesium(Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium(Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or anycombination thereof may be used. However, the material for forming thefirst electrode 110 is not limited thereto.

The first electrode 11 may have a single-layered structure, or amulti-layered structure including two or more layers.

HOMO Energy Levels of Hole Transport Region 12, Intermediate Layer 13,and Emission Layer 15

The organic layer 10A may include an emission layer 15, and anintermediate layer 13 disposed between the first electrode 11 and theemission layer 15. The intermediate layer 13 directly contacts theemission layer 15. That is, no layer is disposed between theintermediate layer 13 and the emission layer 15.

The intermediate layer 13 may include a first hole transport material,and the emission layer 15 may include a host and a dopant.

The dopant is an organometallic compound, and the dopant does notinclude iridium. That is, the dopant is an iridium-free organometalliccompound.

The organic light-emitting device 10 may satisfy a condition ofHOMO(h1)−HOMO(host)<0 electron volts (eV). HOMO(h1) indicates thehighest occupied molecular orbital (HOMO) energy level (eV) of the firsthole transport material included in the intermediate layer 13, i) whenthe host consists of a single host, the HOMO(host) indicates a HOMOenergy level (eV) of the single host and ii) when the host is a mixtureof two or more different hosts, the HOMO(host) indicates the highestenergy level among HOMO energy levels (eV) of the two or more differenthosts. HOMO(h1) and HOMO(host) are respectively measured with respect tothe first hole transport material and the host by using a photoelectronspectrometer in an ambient atmosphere.

Since the organic light-emitting device 10 satisfies the condition ofHOMO(h1)−HOMO(host)<0 eV, holes moved to the emission layer 15 may beeasily trapped into the emission layer 15. Therefore, since the holeinjection into the emission layer 15 is facilitated, reduction of adriving voltage, prevention of interfacial degradation between theintermediate layer 13 and the emission layer 15, prevention of luminancereduction according to a driving time (long lifespan), and a highexternal quantum efficiency, and the like for the organic light-emittingdevice 10 may be achieved.

In an embodiment, the organic light-emitting device 10 may satisfy acondition of:

−0.4 eV≤HOMO(h1)−HOMO(host)<0 eV;

−0.3 eV≤HOMO(h1)−HOMO(host)<0 eV;

−0.2 eV≤HOMO(h1)−HOMO(host)<0 eV;

−0.11 eV≤HOMO(h1)−HOMO(host)<0 eV;

−0.08 eV≤HOMO(h1)−HOMO(host)<0 eV; or

−0.01 eV≤HOMO(h1)−HOMO(host)<0 eV,

but embodiments of the present disclosure are not limited thereto.

In an embodiment, the organic light-emitting device 10 may satisfy acondition of:

HOMO(dopant)−HOMO(host)<0.40 eV;

HOMO(dopant)−HOMO(host)<0.35 eV; or

HOMO(dopant)−HOMO(host)<0.30 eV.

HOMO(dopant) is a HOMO energy level (eV) of the dopant included in theemission layer 15, and HOMO(dopant) is measured by using a photoelectronspectrometer in an ambient atmosphere.

Since the organic light-emitting device 10 satisfies the condition ofHOMO(dopant)−HOMO(host)<0.40 eV, the dopant included in the emissionlayer 15 may act as a shallow trapping site with respect to the holeinjected into the emission layer 15. Thus, retardation of hole hoppingtransport in the emission layer 15 may be substantially prevented.Consequently, the luminescent efficiency and lifespan of the organiclight-emitting device 10 may be improved.

In an embodiment, the organic light-emitting device 10 may satisfy acondition of:

0 eV<HOMO(dopant)−HOMO(host)≤0.30 eV;

0 eV<HOMO(dopant)−HOMO(host)≤0.25 eV;

0 eV<HOMO(dopant)−HOMO(host)≤0.21 eV;

0 eV<HOMO(dopant)−HOMO(host)≤0.17 eV; or

0 eV<HOMO(dopant)−HOMO(host)≤0.14 eV,

but embodiments of the present disclosure are not limited thereto.

The organic light-emitting device 10 may further include a holetransport region 12 disposed between the first electrode 11 and theintermediate layer 13, and the hole transport region 12 may include asecond hole transport material and satisfy a condition ofHOMO(h1)−HOMO(h2)<0 eV. HOMO(h2) is a HOMO energy level of the secondhole transport material, and HOMO(h2) is measured by using aphotoelectron spectrometer.

The hole transport region 12 may have a single-layered structure or amulti-layered structure. For example, the hole transport region 12 mayhave a structure of hole injection layer, hole transport layer, holeinjection layer/hole transport layer, or hole injection layer/first holetransport layer/second hole transport layer, but embodiments of thepresent disclosure are not limited thereto.

Since the organic light-emitting device 10 satisfies the condition ofHOMO(h1)−HOMO(h2)<0 eV, hole injection and transport from the holetransport region 12 to the intermediate layer 13 may be facilitated.

FIG. 2 is a diagram showing HOMO(h2), HOMO(h1), HOMO(host), andHOMO(dopant) of the organic light-emitting device 10.

Referring to FIG. 2, the organic light-emitting device 10 may furthersatisfy at least one of the following conditions, in addition to thecondition of HOMO(h1)−HOMO(host)<0 eV:

HOMO(h1)<HOMO(h2)

HOMO(h1)<HOMO(host)<HOMO(h2)

HOMO(h1)<HOMO(dopant)<HOMO(h2)

HOMO(h1)<HOMO(host)<HOMO(dopant)<HOMO(h2)

HOMO(h1)<HOMO(dopant)

HOMO(h1)<HOMO(host)<HOMO(dopant)

HOMO(host)<HOMO(dopant)

HOMO(h2), HOMO(h1), HOMO(host), and HOMO(dopant) of FIG. 2 are actualmeasurement values measured by using a photoelectron spectrometer in anambient atmosphere and are negative values.

Dopant in Emission Layer 15

The dopant in the emission layer 15 may be a phosphorescent compound.Thus, the organic light-emitting device 10 is quite different from anorganic light-emitting device that emits fluorescence through afluorescence mechanism.

In one or more embodiments, the dopant may be an organometallic compoundincluding platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr),hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), rhodium (Rh),ruthenium (Ru), rhenium (Re), beryllium (Be), magnesium (Mg), aluminum(Al), calcium (Ca), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn),gallium (Ga), germanium (Ge), rhodium (Rh), palladium (Pd), silver (Ag),or gold (Au). For example, the dopant may be an organometallic compoundincluding platinum (Pt) or palladium (Pd), but embodiments of thepresent disclosure are not limited thereto.

In one or more embodiments, the dopant may include a metal M and anorganic ligand, and the metal M and the organic ligand may form one,two, or three cyclometallated rings. The metal M may be platinum (Pt),osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu),terbium (Tb), thulium (Tm), rhodium (Rh), ruthenium (Ru), rhenium (Re),beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca), manganese(Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge),rhodium (Rh), palladium (Pd), silver (Ag), or gold (Au).

In one or more embodiments, the dopant may include a metal M and atetradentate organic ligand capable of forming three or four (forexample, three) cyclometallated rings with the metal M. The metal M isthe same as described above. The tetradentate organic ligand mayinclude, for example, a benzimidazole group and a pyridine group, butembodiments of the present disclosure are not limited thereto.

In one or more embodiments, the dopant may include a metal M and atleast one of ligands represented by Formulae 1-1 to 1-4:

In Formulae 1-1 to 1-4,

A₁ to A₄ may each independently be selected from a substituted orunsubstituted C₅-C₃₀ carbocyclic group, a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, and a non-cyclic group,

Y₁₁ to Y₁₄ may each independently be a chemical bond, O, S, N(R₉₁),B(R₉₁), P(R₉₁), or C(R₉₁)(R₉₂),

T₁ to T₄ may each independently be selected from a single bond, a doublebond, *—N(R₉₃)—*′, *—B(R₉₃)—*′, *—P(R₉₃)—*′, *—C(R₉₃)(R₉₄)—*′,*—Si(R₉₃)(R₉₄)—*′, *—Ge(R₉₃)(R₉₄)—*′, *—S—*′, *—Se—*′, *—O—*′,*—C(═O)—*′, *—S(═O)—*′, *—S(═O)₂—*′, *—C(R₉₃)═*′, *═C(R₉₃)—*′,*—C(R₉₃)═C(R₉₄)—*′, *—C(═S)—*′, and *—C≡C—*′,

a substituent of the substituted C₅-C₃₀ carbocyclic group, a substituentof the substituted C₁-C₃₀ heterocyclic group, and R₉₁ to R₉₄ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I,—SF₅, a hydroxyl group, a cyano group, a nitro group, an amidino group,a hydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₇-C₆₀ arylalkylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substitutedor unsubstituted C₁-C₆₀ heteroarylthio group, a substituted orunsubstituted C₂-C₆₀ heteroarylalkyl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and—P(═O)(Q₈)(Q₉), and

*₁, *₂, *₃, and *₄ each indicate a binding site to M of the dopant.

For example, the dopant may include a ligand represented by Formula 1-3,and one of A₁ to A₄ in Formula 1-3 may be a substituted or unsubstitutedbenzimidazole group and at least one of the remainder of A₁ to A₄ may bea substituted or unsubstituted pyridine group, but embodiments of thepresent disclosure are not limited thereto.

In one or more embodiments, the dopant may be an organometallic compoundrepresented by Formula 1A:

In Formula 1A,

M may be beryllium (Be), magnesium (Mg), aluminum (Al), calcium (Ca),titanium (Ti), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn),gallium (Ga), germanium (Ge), zirconium (Zr), ruthenium (Ru), rhodium(Rh), palladium (Pd), silver (Ag), rhenium (Re), platinum (Pt), or gold(Au),

X₁ may be O or S, and a bond between X₁ and M may be a covalent bond,

X₂ to X₄ may each independently be C or N,

one bond selected from a bond between X₂ and M, a bond between X₃ and M,and a bond between X₄ and M may be a covalent bond, and the othersthereof may each be a coordinate bond,

Y₁ and Y₃ to Y₅ may each independently be C or N,

a bond between X₂ and Y₃, a bond between X₂ and Y₄, a bond between Y₄and Y₅, a bond between Y₅ and X₅₁, and a bond between X₅₁ and Y₃ mayeach be a chemical bond,

CY₁ to CY₅ may each independently be a C₅-C₃₀ carbocyclic group or aC₁-C₃₀ heterocyclic group, and CY₄ is not a benzimidazole group,

a cyclometallated ring formed by CY₅, CY₂, CY₃, and M may be a6-membered ring,

X₅₁ may be selected from O, S, N-[(L₇)_(b7)-(R₇)_(c7)], C(R₇)(R₈),Si(R₇)(R₈), Ge(R₇)(R₈), C(═O), N, C(R₇), Si(R₇), and Ge(R₇),

R₇ and R₈ may optionally be linked via a first linking group to form asubstituted or unsubstituted C₅-C₃₀ carbocyclic group or a substitutedor unsubstituted C₁-C₃₀ heterocyclic group,

L₁ to L₄ and L₇ may each independently be a substituted or unsubstitutedC₅-C₃₀ carbocyclic group or a substituted or unsubstituted C₁-C₃₀heterocyclic group,

b1 to b4 and b7 may each independently be an integer from 0 to 5,

R₁ to R₄, R₇, and R₈ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₇-C₆₀ arylalkyl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀heteroarylthio group, a substituted or unsubstituted C₂-C₆₀heteroarylalkyl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, a substituted or unsubstitutedmonovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂),—Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉),

c1 to c4 may each independently be an integer from 1 to 5,

a1 to a4 may each independently be 0, 1, 2, 3, 4, or 5,

two of a plurality of neighboring groups R₁ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₂ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₃ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

two of a plurality of neighboring groups R₄ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group, and

two or more groups selected from R₁ to R₄ may optionally be linked toform a substituted or unsubstituted C₅-C₃₀ carbocyclic group or asubstituted or unsubstituted C₁-C₃₀ heterocyclic group.

A C₅-C₃₀ carbocyclic group, a C₁-C₃₀ heterocyclic group, and a CY₁ toCY₄ in Formulae 1-1 to 1-4 and 1A may each independently be a) a6-membered ring, b) a condensed ring with two or more 6-membered rings,or c) a condensed ring with at least one 6-membered ring and one5-membered ring; the 6-membered ring may be selected from a cyclohexanegroup, a cyclohexene group, an adamantane group, a norbornane group, anorbornene group, a benzene group, a pyridine group, a pyrimidine group,a pyrazine group, a pyridazine group, and a triazine group; and the5-membered ring may be selected from a cyclopentane group, acyclopentene group, a cyclopentadiene group, a furan group, a thiophenegroup, a silole group, a pyrrole group, a pyrazole group, an imidazolegroup, a triazole group, an oxazole group, an isoxazole group, athiazole group, an isothiazole group, an oxadiazole group, and athiadiazole group.

A non-cyclic group in Formulae 1-1 to 1-4 may be *—C(═O)—*′,*—S—C(═O)—*′, *—O—C(═S)—*′, or *—S—C(═S)—*′, but embodiments of thepresent disclosure are not limited thereto.

A substituent of the substituted C₅-C₃₀ carbocyclic group, a substituentof the substituted C₁-C₃₀ heterocyclic group, R₉₁ to R₉₄, R₁ to R₄, R₇,and R₈ in Formulae 1-1 to 1-4 and 1A may each independently be selectedfrom:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazine group, ahydrazone group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,—SF₅, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₁₀ alkylgroup, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclooctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a pyridinylgroup, and a pyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclooctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclooctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, and animidazopyrimidinyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,—CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group,an amidino group, a hydrazine group, a hydrazone group, a carboxylicacid group or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptylgroup, a cyclooctyl group, an adamantanyl group, a norbornanyl group, anorbornenyl group, a cyclopentenyl group, a cyclohexenyl group, acycloheptenyl group, a phenyl group, a naphthyl group, a fluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, apyrrolyl group, a thiophenyl group, a furanyl group, an imidazolylgroup, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, anoxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinylgroup, a pyrimidinyl group, a pyridazinyl group, an isoindolyl group, anindolyl group, an indazolyl group, a purinyl group, a quinolinyl group,an isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl group, aquinazolinyl group, a cinnolinyl group, a carbazolyl group, aphenanthrolinyl group, a benzimidazolyl group, a benzofuranyl group, abenzothiophenyl group, an isobenzothiazolyl group, a benzoxazolyl group,an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, anoxadiazolyl group, a triazinyl group, a dibenzofuranyl group, adibenzothiophenyl group, a dibenzosilolyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, an imidazopyridinyl group, animidazopyrimidinyl group, and —Si(Q₃₃)(Q₃₄)(Q₃₅); and

—N(Q₁)(Q₂), —Si(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), and —P(═O)(Q₈)(Q₉), and

Q₁ to Q₉ and Q₃₃ to Q₃₅ may each independently be selected from:

—CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂, —CHDCH₃,—CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, and —CD₂CDH₂;

an n-propyl group, an iso-propyl group, an n-butyl group, an isobutylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group; and

an n-propyl group, an iso-propyl group, an n-butyl group, an isobutylgroup, a sec-butyl group, a tert-butyl group, an n-pentyl group, anisopentyl group, a sec-pentyl group, a tert-pentyl group, a phenylgroup, and a naphthyl group, each substituted with at least one selectedfrom deuterium, a C₁-C₁₀ alkyl group, and a phenyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the dopant is an organometallic compoundrepresented by Formula 1A, provided that, in Formula 1A,

X₂ and X₃ are each independently C or N,

X₄ may be N, and

when i) M is Pt, ii) X₁ is O, iii) X₂ and X₄ are each N, X₃ is C, a bondbetween X₂ and M and a bond between X₄ and M are each a coordinate bond,and a bond between X₃ and M is a covalent bond, iv) Y₁ to Y₅ are each C,v) a bond between Y₅ and X₅₁ and a bond between Y₃ and X₅₁ are each asingle bond, vi) CY₁, CY₂, and CY₃ are each a benzene group, and CY₄ isa pyridine group, vii) X₅₁ is O, S, or N-[(L₇)_(b7)-(R₇)_(c7)], andviii) b7 is 0, c7 is 1, and R₇ is a substituted or unsubstituted C₁-C₆₀alkyl group, a1 to a4 may each independently be 1, 2, 3, 4, or 5, and atleast one of R₁ to R₄ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group.

In one or more embodiments, the dopant may be represented by Formula1A-1:

In Formula 1A-1,

M, X₁ to X₃, and X₅₁ are each independently the same as describedherein,

X₁₁ may be N or C-[(L₁₁)_(b11)-(R₁₁)_(c11)], X₁₂ may be N orC-[(L₁₂)_(b12)-(R₁₂)_(c12)], X₁₃ may be N orC-[(L₁₃)_(b13)-(R₁₃)_(c13)], and X₁₄ may be N orC-[(L₁₄)_(b14)-(R₁₄)_(c14)],

L₁₁ to L₁₄, b11 to b14, R₁₁ to R₁₄, and c11 to c14 are eachindependently the same as described in connection with Li, b1, R₁, andc1,

X₂₁ may be N or C-[(L₂₁)_(b21)-(R₂₁)_(c21)], X₂₂ may be N orC-[(L₂₂)_(b22)-(R₂₂)_(c22)], and X₂₃ may be N orC-[(L₂₃)_(b23)-(R₂₃)_(c23)],

L₂₁ to L₂₃, b21 to b23, R₂₁ to R₂₃, and c21 to c23 are eachindependently the same as described in connection with L₂, b2, R₂, andc2,

X₃₁ may be N or C-[(L₃₁)_(b31)-(R₃₁)_(c31)], X₃₂ may be N orC-[(L₃₂)_(b32)-(R₃₂)_(c32)], and X₃₃ may be N orC-[(L₃₃)_(b33)-(R₃₃)_(c33)],

L₃₁ to L₃₃, b31 to b33, R₃₁ to R₃₃, and c31 to c33 are eachindependently the same as described in connection with L₃, b3, R₃, andc3,

X₄₁ may be N or C-[(L₄₁)_(b41)-(R₄₁)_(c41)], X₄₂ may be N orC-[(L₄₂)_(b42)-(R₄₂)_(c42)], X₄₃ may be N orC-[(L₄₃)_(b43)-(R₄₃)_(c43)], and X₄₄ may be N orC-[(L₄₄)_(b44)-(R₄₄)_(c44)],

L₄₁ to L₄₄, b41 to b44, R₄₁ to R₄₄, and c41 to c44 are eachindependently the same as described in connection with L₄, b4, R₄, andc4,

two of R₁₁ to R₁₄ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group,

two of R₂₁ to R₂₃ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group,

two of R₃₁ to R₃₃ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group, and

two of R₄₁ to R₄₄ may optionally be linked to form a substituted orunsubstituted C₅-C₃₀ carbocyclic group or a substituted or unsubstitutedC₁-C₃₀ heterocyclic group.

For example, the dopant may be one of Compounds 1-1 to 1-88, 2-1 to2-47, and 3-1 to 3-582, but embodiments of the present disclosure arenot limited thereto:

Host in Emission Layer 15

The host in the emission layer 15 may be a single compound or a mixtureof two or more different compounds.

In an embodiment, the host may include an electron transport hostincluding at least one electron transport moiety, and a hole transporthost including no electron transport moiety. HOMO(host) defined hereinmay be the same as the HOMO energy level of the hole transport host.

The electron transport moiety may be selected from a cyano group, a πelectron-depleted nitrogen-containing cyclic group, and a grouprepresented by one of the following formulae:

In these formulae, *, *′, and *″ each indicate a binding site to aneighboring atom.

In one or more embodiments, the host may include an electron transporthost and a hole transport host, wherein the electron transport host mayinclude at least one π electron-depleted nitrogen-free cyclic group andat least one electron transport moiety, and the hole transport host mayinclude at least one π electron-depleted nitrogen-free cyclic group andmay not include an electron transport moiety.

The π electron-depleted nitrogen-containing cyclic group is a cyclicgroup having at least one *—N=*′ moiety and may be, for example, animidazole group, a pyrazole group, a thiazole group, an isothiazolegroup, an oxazole group, an isoxazole group, a pyridine group, apyrazine group, a pyridazine group, a pyrimidine group, an indazolegroup, a purine group, a quinoline group, an isoquinoline group, abenzoquinoline group, a phthalazine group, a naphthyridine group, aquinoxaline group, a quinazoline group, a cinnoline group, aphenanthridine group, an acridine group, a phenanthroline group, aphenazine group, a benzimidazole group, an isobenzothiazole group, abenzoxazole group, an isobenzoxazole group, a triazole group, atetrazole group, an oxadiazole group, a triazine group, a thiadiazolegroup, an imidazopyridine group, an imidazopyrimidine group, and anazacarbazole group.

The π electron-depleted nitrogen-free cyclic group may be selected froma benzene group, a heptalene group, an indene group, a naphthalenegroup, an azulene group, an indacene group, an acenaphthylene group, afluorene group, a spiro-bifluorene group, a benzofluorene group, adibenzofluorene group, a phenalene group, a phenanthrene group, ananthracene group, a fluoranthene group, a triphenylene group, a pyrenegroup, a chrysene group, a naphthacene group, a picene group, a perylenegroup, a pentacene group, a hexacene group, a pentaphene group, arubicene group, a corozene group, an ovalene group, a pyrrole group, anisoindole group, an indole group, a furan group, a thiophene group, abenzofuran group, a benzothiophene group, a benzocarbazole group, adibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group,a dibenzothiophene sulfone group, a carbazole group, a dibenzosilolegroup, an indenocarbazole group, an indolocarbazole group, abenzofurocarbazole group, a benzothioenocarbazole group, and atriindolobenzene group, but embodiments of the present disclosure arenot limited thereto.

In an embodiment, the electron transport host may be selected fromcompounds represented by Formula E-1, and

the hole transport host may be selected from compounds represented byFormula H-1, but embodiments of the present disclosure are not limitedthereto:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21).  Formula E-1

In Formula E-1,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group ora substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3, and

L₃₀₁ may be selected from a single bond, a group represented by one ofthe following formulae, a substituted or unsubstituted C₅-C₆₀carbocyclic group, and a substituted or unsubstituted C₁-C₆₀heterocyclic group, and *, *′, and *″ in the following formulae eachindicate a binding site to a neighboring atom:

xb1 may be an integer from 1 to 5,

R₃₀₁ may be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₇-C₆₀ arylalkylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substitutedor unsubstituted C₁-C₆₀ heteroarylthio group, a substituted orunsubstituted C₂-C₆₀ heteroarylalkyl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), —S(═O)(Q₃₀₁),—P(═O)(Q₃₀₁)(Q₃₀₂), and —P(═S)(Q₃₀₁)(Q₃₀₂),

xb21 may be an integer from 1 to 5,

Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkylgroup, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group,

the organic light-emitting device satisfies at least one of Condition 1to Condition 3:

Condition 1

at least one of Ar₃₀₁, L₃₀₁, and R₃₀₁ in Formula E-1 includes a πelectron-depleted nitrogen-containing cyclic group,

Condition 2

at least one of L₃₀₁ in Formula E-1 is a group represented by one of thefollowing formulae:

and

Condition 3

at least one of R₃₀₁ in Formula E-1 is selected from a cyano group,—S(═O)₂(Q₃₀₁), —S(═O)(Q₃₀₁), —P(═O)(Q₃₀₁)(Q₃₀₂), and —P(═S)(Q₃₀₁)(Q₃₀₂).

In Formulae H-1, 11, and 12,

L₄₀₁ may be selected from:

a single bond; and

a benzene group, a heptalene group, an indene group, a naphthalenegroup, an azulene group, an indacene group, an acenaphthylene group, afluorene group, a spiro-bifluorene group, a benzofluorene group, adibenzofluorene group, a phenalene group, a phenanthrene group, ananthracene group, a fluoranthene group, a triphenylene group, a pyrenegroup, a chrysene group, a naphthacene group, a picene group, a perylenegroup, a pentacene group, a hexacene group, a pentaphene group, arubicene group, a corozene group, an ovalene group, a pyrrole group, aniso-indole group, an indole group, a furan group, a thiophene group, abenzofuran group, a benzothiophene group, a benzocarbazole group, adibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group,a dibenzothiophene sulfone group, a carbazole group, a dibenzosilolegroup, an indenocarbazole group, an indolocarbazole group, abenzofurocarbazole group, a benzothioenocarbazole group, and atriindolobenzene group, each unsubstituted or substituted with at leastone selected from deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a naphthyl group, a fluorenyl group, a carbazolylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, atriphenylenyl group, a biphenyl group, a terphenyl group, a tetraphenylgroup, and —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃),

xd1 may be an integer from 1 to 10, wherein, when xd1 is two or more,two or more groups L₄₀₁ may be identical to or different from eachother,

Ar₄₀₁ may be selected from groups represented by Formulae 11 and 12,

Ar₄₀₂ may be selected from:

groups represented by Formulae 11 and 12, a phenyl group, a naphthylgroup, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a biphenyl group, a terphenyl group, and atriphenylenyl group; and

a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, aterphenyl group, and a triphenylenyl group, each substituted with atleast one selected from deuterium, a hydroxyl group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, abiphenyl group, a terphenyl group, and a triphenylenyl group,

CY₄₀₁ and CY₄₀₂ may each independently be selected from a benzene group,a naphthalene group, a fluorene group, a carbazole group, abenzocarbazole group, an indolocarbazole group, a dibenzofuran group, adibenzothiophene group, a dibenzosilole group, a benzonaphthofurangroup, a benzonaphthothiophene group, and a benzonaphthosilole group,

A₂₁ may be selected from a single bond, O, S, N(R₅₁), C(R₅₁)(R₅₂), andSi(R₅₁)(R₅₂),

A₂₂ may be selected from a single bond, O, S, N(R₅₃), C(R₅₃)(R₅₄), andSi(R₅₃)(R₅₄),

at least one of A₂₁ and A₂₂ in Formula 12 may not be a single bond,

R₅₁ to R₅₄, R₆₀, and R₇₀ may each independently be selected from:

hydrogen, deuterium, a hydroxyl group, an amino group, an amidino group,a hydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxygroup;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, a hydroxyl group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a phenyl group, a naphthylgroup, a fluorenyl group, a carbazolyl group, a dibenzofuranyl group,and a dibenzothiophenyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, aterphenyl group, and a triphenylenyl group;

a phenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group,a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, aterphenyl group, and a triphenylenyl group, each substituted with atleast one selected from deuterium, a hydroxyl group, an amino group, anamidino group, a hydrazine group, a hydrazone group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, acarbazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, anda biphenyl group; and

—Si(Q₄₀₄)(Q₄₀₅)(Q₄₀₆),

e1 and e2 may each independently be an integer from 0 to 10,

Q₄₀₁ to Q₄₀₆ may each independently be selected from hydrogen,deuterium, a hydroxyl group, an amino group, an amidino group, ahydrazine group, a hydrazone group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a phenyl group, a naphthyl group, a fluorenylgroup, a carbazolyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a biphenyl group, a terphenyl group, and a triphenylenyl group,and

* indicates a binding site to a neighboring atom.

In an embodiment, in Formula E-1, Ar₃₀₁ may be selected from anaphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each unsubstituted or substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

at least one of groups L₃₀₁ in the number of xb1 may be selected from animidazole group, a pyrazole group, a thiazole group, an isothiazolegroup, an oxazole group, an isoxazole group, a pyridine group, apyrazine group, a pyridazine group, a pyrimidine group, an indazolegroup, a purine group, a quinoline group, an isoquinoline group, abenzoquinoline group, a phthalazine group, a naphthyridine group, aquinoxaline group, a quinazoline group, a cinnoline group, aphenanthridine group, an acridine group, a phenanthroline group, aphenazine group, a benzimidazole group, an isobenzothiazole group, abenzoxazole group, an isobenzoxazole group, a triazole group, atetrazole group, an oxadiazole group, a triazine group, a thiadiazolegroup, an imidazopyridine group, an imidazopyrimidine group, and anazacarbazole group, each unsubstituted or substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),—N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and—P(═O)(Q₃₁)(Q₃₂),

R₃₀₁ may be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, atetraphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group,a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group, but embodiments of the present disclosureare not limited thereto.

In one or more embodiments, R₃₀₁ may be selected from groups representedby Formulae 7-1 to 7-9, but embodiments of the present disclosure arenot limited thereto:

The electron transport host may be selected from Compounds H-E1 toH-E84, but embodiments of the present disclosure are not limitedthereto:

In an embodiment, the hole transport host may be selected from CompoundsH-H1 to H-H103, but embodiments of the present disclosure are notlimited thereto:

In an embodiment, the host may include an electron transport host and ahole transport host, the electron transport host may include atriphenylene group and a triazine group, and the hole transport host mayinclude a carbazole group, but embodiments of the present disclosure arenot limited thereto.

A weight ratio of the electron transport host to the hole transport hostmay be in a range of 1:9 to 9:1, for example, 2:8 to 8:2. In anembodiment, the weight ratio of the electron transport host to the holetransport host may be in a range of 4:6 to 6:4. While not wishing to bebound by theory, it is understood that when the weight ratio of theelectron transport host to the hole transport host is within theseranges, hole and electron transport balance into the emission layer 15may be achieved.

First Hole Transport Material of Intermediate Layer 13 and Second HoleTransport Material of Hole Transport Region 12

The first hole transport material included in the intermediate layer 13may be selected from materials satisfying a condition ofHOMO(h1)−HOMO(host)<0.

For example, the first hole transport material included in theintermediate layer 13 and the second hole transport material included inthe hole transport region 12 may each independently be selected fromamine-based compounds.

In an embodiment, the first hole transport material and the second holetransport material may each independently be selected from amine-basedcompounds satisfying a condition of HOMO(h1)−HOMO(h2)<0.

In an embodiment, the first hole transport material may be differentfrom the second hole transport material.

In an embodiment, the first hole transport material and the second holetransport material may each independently be selected from compoundsrepresented by Formulae 201 to 205, but embodiments of the presentdisclosure are not limited thereto:

In Formulae 201 to 205,

L₂₀₁ to L₂₀₉ may each independently be *—O—*′, *—S—*′, a substituted orunsubstituted C₅-C₆₀ carbocyclic group, or a substituted orunsubstituted C₁-C₆₀ heterocyclic group,

xa1 to xa9 may each independently be an integer from 0 to 5, and

R₂₀₁ to R₂₀₆ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₇-C₆₀ arylalkyl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀heteroarylthio group, a substituted or unsubstituted C₂-C₆₀heteroarylalkyl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and two neighboring groups selected from R₂₀₁ to R₂₀₆ may optionally belinked via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group.

For example, L₂₀₁ to L₂₀₉ may be selected from a benzene group, aheptalene group, an indene group, a naphthalene group, an azulene group,an indacene group, an acenaphthylene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentacene group, a hexacene group, a pentaphene group, a rubicene group,a corozene group, an ovalene group, a pyrrole group, an iso-indolegroup, an indole group, a furan group, a thiophene group, a benzofurangroup, a benzothiophene group, a benzocarbazole group, adibenzocarbazole group, a dibenzofuran group, a dibenzothiophene group,a dibenzothiophene sulfone group, a carbazole group, a dibenzosilolegroup, an indenocarbazole group, an indolocarbazole group, abenzofurocarbazole group, a benzothioenocarbazole group, and atriindolobenzene group, each unsubstituted or substituted with at leastone selected from deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a naphthyl group, a fluorenyl group, a carbazolylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, atriphenylenyl group, a biphenyl group, a terphenyl group, a tetraphenylgroup, and —Si(Q₁₁)(Q₁₂)(Q₁₃),

xa1 to xa9 may each independently be 0, 1, or 2, and

R₂₀₁ to R₂₀₆ may each independently be selected from a phenyl group, abiphenyl group, a terphenyl group, a pentalenyl group, an indenyl group,a naphthyl group, an azulenyl group, a heptalenyl group, an indacenylgroup, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenylgroup, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, anaphthacenyl group, a picenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a rubicenyl group, acoronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group,a carbazolyl group, an indolyl group, an isoindolyl group, abenzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, a pyridinyl group, an indeno carbazolylgroup, an indolocarbazolyl group, a benzofurocarbazolyl group, and abenzothienocarbazolyl group, each unsubstituted or substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a pentalenyl group, anindenyl group, a naphthyl group, an azulenyl group, a heptalenyl group,an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂).

In one or more embodiments, the first hole transport material of theintermediate layer 13 may be selected from carbazole group-freeamine-based compounds.

In one or more embodiments, the first hole transport material of theintermediate layer 13 may be selected from compounds represented byFormula 201, which do not include a carbazole group.

In one or more embodiments, the first hole transport material of theintermediate layer 13 be selected from compounds represented by Formula201, which do not include a carbazole group and include at least one ofa dibenzofuran group, a dibenzothiophene group, a fluorene group, aspiro-bifluorene group, an indenocarbazole group, an indolocarbazolegroup, a benzofurocarbazole group, and a benzothienocarbazole group.

In one or more embodiments, the first hole transport material of theintermediate layer 13 is selected from compounds represented by Formula202, provided that, in Formula 202, xa5 is 1, 2, or 3, xa3 and xa4 areeach 0, and R₂₀₃ and R₂₀₄ are linked via a single bond, adimethyl-methylene group, or a diphenyl-methylene group.

In one or more embodiments, the second hole transport material of thehole transport region 12 may be selected from carbazole group-containingamine-based compounds.

In one or more embodiments, the second hole transport material of thehole transport region 12 may be selected from compounds represented byFormula 201, which include a carbazole group and further include atleast one of a dibenzofuran group, a dibenzothiophene group, a fluorenegroup, a spiro-bifluorene group, an indenocarbazole group, anindolocarbazole group, a benzofurocarbazole group, and abenzothienocarbazole group.

In one or more embodiments, the second hole transport material of thehole transport region 12 may be selected from compounds represented byFormula 201 or 202, which include a carbazole group.

In one or more embodiments, the first hole transport material of theintermediate layer 13 may be selected from compounds represented byFormula 201-1 or 202-1, and the second hole transport material of thehole transport region 12 may be selected from compounds represented byFormula 201-2, but embodiments of the present disclosure are not limitedthereto:

In Formulae 201-1, 202-1, and 201-2, L₂₀₁ to L₂₀₃, L₂₀₅, xa1 to xa3,xa5, R₂₀₁, and R₂₀₂ are each independently the same as described herein,and R₂₁₁ to R₂₁₃ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, aphenyl group substituted with —F, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a dimethylfluorenyl group, a diphenyl fluorenylgroup, a triphenylenyl group, a thiophenyl group, a furanyl group, acarbazolyl group, an indolyl group, an isoindolyl group, a benzofuranylgroup, a benzothiophenyl group, a dibenzofuranyl group, adibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolylgroup, a dibenzosilolyl group, and a pyridinyl group.

For example, the first hole transport material may be selected fromCompounds HT3 to HT5, HT16 to HT24, HT35, and HT37 to HT39, and thesecond hole transport material may be selected from HT1, HT2, HT6 toHT15, HT25 to HT34, and HT36, but embodiments of the present disclosureare not limited thereto:

The intermediate layer 13 of the organic light-emitting device 10 maynot include a p-dopant. For example, the intermediate layer 13 mayinclude at least one of the compound belonging to the first holetransport material.

The hole transport region 12 of the organic light-emitting device 10 mayfurther include a p-dopant. When the hole transport region 12 furtherincludes the p-dopant, the hole transport region 12 may have a structureincluding a matrix (second hole transport material) and a p-dopantincluded in the matrix. The p-dopant may be homogeneously ornon-homogeneously doped in the hole transport region 12.

In an embodiment, the p-dopant may have the lowest unoccupied molecularorbital (LUMO) energy level of about −3.5 eV or less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butembodiments of the present disclosure are not limited thereto.

For example, the p-dopant may include at least one selected from:

a quinone derivative such as tetracyanoquinodimethane (TCNQ),2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), andF6-TCNNQ;

a metal oxide such as a tungsten oxide and a molybdenum oxide;1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221,

but embodiments of the present disclosure are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, provided that at leastone of R₂₂₁ to R₂₂₃ has at least one substituent selected from a cyanogroup, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substituted with —F, aC₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

A thickness of the hole transport region 12 may be in a range of about100 Angstroms (Å) to about 10,000 Å, for example, about 400 Å to about2,000 Å, a thickness of the intermediate layer 13 may be in a range ofabout 100 Å to about 1,000 Å, for example, about 200 Å to about 500 Å,and a thickness of the emission layer 15 may be in a range of about 100Å to about 3,000 Å, for example, about 300 Å to about 1,000 Å. While notwishing to be bound by theory, it is understood that when thethicknesses of the hole transport region 12, the intermediate layer 13,and the emission layer 15 are within these ranges, satisfactory holetransporting characteristics and/or luminescence characteristics may beobtained without a substantial increase in driving voltage.

Electron Transport Region 17

An electron transport region 17 may be disposed between the emissionlayer 15 and the second electrode 19 in the organic light-emittingdevice 10.

The electron transport region 17 may have a single-layered structure ora multi-layered structure.

For example, the electron transport region 17 may have a structure ofelectron transport layer, electron transport layer/electron injectionlayer, buffer layer/electron transport layer, hole blockinglayer/electron transport layer, buffer layer/electron transportlayer/electron injection layer, or hole blocking layer/electrontransport layer/electron injection layer, but embodiments of the presentdisclosure are not limited thereto. For example, the electron transportregion 17 may additionally have an electron control layer.

The electron transport region 17 may include a known electron transportmaterial.

The electron transport region (for example, the buffer layer, the holeblocking layer, the electron control layer, or the electron transportlayer in the electron transport region) may include a metal-freecompound including at least one π electron-depleted nitrogen-containingcyclic group. The π electron-depleted nitrogen-containing cyclic groupis the same as described above.

For example, the electron transport region may include a compoundrepresented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21).  Formula 601

In Formula 601,

Ar₆₀₁ and L₆₀₁ may each independently be a substituted or unsubstitutedC₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

xe11 may be 1, 2, or 3,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₇-C₆₀ arylalkylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substitutedor unsubstituted C₁-C₆₀ heteroarylthio group, a substituted orunsubstituted C₂-C₆₀ heteroarylalkyl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or anaphthyl group, and

xe21 may be an integer from 1 to 5.

In an embodiment, at least one of groups Ar₆₀₁ in the number of xe11 andat least one of groups R₆₀₁ in the number of xe21 may include the πelectron-depleted nitrogen-containing cyclic group.

In an embodiment, in Formula 601, ring Ar₆₀₁ and ring L₆₀₁ may eachindependently be selected from a benzene group, a naphthalene group, afluorene group, a spiro-bifluorene group, a benzofluorene group, adibenzofluorene group, a phenalene group, a phenanthrene group, ananthracene group, a fluoranthene group, a triphenylene group, a pyrenegroup, a chrysene group, a naphthacene group, a picene group, a perylenegroup, a pentaphene group, an indenoanthracene group, a dibenzofurangroup, a dibenzothiophene group, a carbazole group, an imidazole group,a pyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an iso-benzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, eachunsubstituted or substituted with at least one selected from deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkylgroup, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and—P(═O)(Q₃₁)(Q₃₂), wherein Q₃₁ to Q₃₃ may each independently be selectedfrom a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, and a naphthyl group.

When xe11 in Formula 601 is two or more, two or more groups Ar₆₀₁ may belinked via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracenegroup.

In one or more embodiments, a compound represented by Formula 601 may berepresented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), and at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be the same as described inconnection with L₆₀₁,

xe611 to xe613 may each independently be the same as described inconnection with xe1

R₆₁₁ to R₆₁₃ may each independently be the same as described inconnection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and601-1 may each independently be 0, 1, or 2.

In one or more embodiments, in Formulae 601 and 601-1, R₆₀₁ and R₆₁₁ toR₆₁₃ may each independently be selected from a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each unsubstituted or substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36, but embodiments of the present disclosureare not limited thereto:

In one or more embodiments, the electron transport region may include atleast one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ:

A thickness of the buffer layer, the hole blocking layer, or theelectron control layer may each independently be in a range of about 20Å to about 1,000 Å, for example, about 30 Å to about 300 Å. While notwishing to be bound by theory, it is understood that when thethicknesses of the buffer layer, the hole blocking layer, and theelectron control layer are within these ranges, the electron blockinglayer may have excellent electron blocking characteristics or electroncontrol characteristics without a substantial increase in drivingvoltage.

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whilenot wishing to be bound by theory, it is understood that when thethickness of the electron transport layer is within the range describedabove, the electron transport layer may have satisfactory electrontransport characteristics without a substantial increase in drivingvoltage.

The electron transport region 17 (for example, the electron transportlayer in the electron transport region) may further include, in additionto the materials described above, a metal-containing material.

The metal-containing material may include at least one selected fromalkali metal complex and alkaline earth-metal complex. The alkali metalcomplex may include a metal ion selected from a Li ion, a Na ion, a Kion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex mayinclude a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Srion, and a Ba ion. A ligand coordinated with the metal ion of the alkalimetal complex or the alkaline earth-metal complex may be selected from ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, ahydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, and a cyclopentadiene, but embodiments of the presentdisclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium8-hydroxyquinolate, LiQ) or ET-D2:

The electron transport region 17 may include an electron injection layerthat facilitates injection of electrons from the second electrode 19.The electron injection layer may directly contact the second electrode19.

The electron injection layer may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In anembodiment, the alkali metal may be Li, Na, or Cs. In one or moreembodiments, the alkali metal may be Li or Cs, but embodiments of thepresent disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and therare earth metal compound may be selected from oxides and halides (forexample, fluorides, chlorides, bromides, or iodides) of the alkalimetal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In an embodiment, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, butembodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), orBa_(x)Ca_(1-x)O (0<x<1). In an embodiment, the alkaline earth-metalcompound may be selected from BaO, SrO, and CaO, but embodiments of thepresent disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, ScO₃,Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In an embodiment, the rare earth metalcompound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃,but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include an ion of alkali metal, alkalineearth-metal, and rare earth metal as described above, and a ligandcoordinated with a metal ion of the alkali metal complex, the alkalineearth-metal complex, or the rare earth metal complex may be selectedfrom hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline,hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxyphenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole,hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene,but embodiments of the present disclosure are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof, as described above. In one or moreembodiments, the electron injection layer may further include an organicmaterial. When the electron injection layer further includes an organicmaterial, an alkali metal, an alkaline earth metal, a rare earth metal,an alkali metal compound, an alkaline earth-metal compound, a rare earthmetal compound, an alkali metal complex, an alkaline earth-metalcomplex, a rare earth metal complex, or any combinations thereof may behomogeneously or non-homogeneously dispersed in a matrix including theorganic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. While notwishing to be bound by theory, it is understood that when the thicknessof the electron injection layer is within the range described above, theelectron injection layer may have satisfactory electron injectioncharacteristics without a substantial increase in driving voltage.

Second Electrode 19

The second electrode 19 may be disposed on the organic layer 10A havingsuch a structure. The second electrode 19 may be a cathode that is anelectron injection electrode, and in this regard, a material for formingthe second electrode 19 may be a material having a low work function,and such a material may be metal, alloy, an electrically conductivecompound, or a combination thereof.

The second electrode 19 may include at least one selected from lithium(Li), silver (Si), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are notlimited thereto. The second electrode 19 may be a transmissiveelectrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 19 may have a single-layered structure, or amulti-layered structure including two or more layers.

Description of FIG. 3

FIG. 3 is a schematic view of an organic light-emitting device 100according to an embodiment.

The organic light-emitting device 100 of FIG. 3 includes a firstelectrode 110, a second electrode 190 facing the first electrode 110,and a first light-emitting unit 151 and a second light-emitting unit 152disposed between the first electrode 100 and the second electrode 190. Acharge-generation layer 141 may be disposed between the firstlight-emitting unit 151 and the second light-emitting unit 152, and thecharge-generation layer 141 may include an n-type charge-generationlayer 141-N and a p-type charge-generation layer 141-P. Thecharge-generation layer 141 is a layer serving to generate charges andsupply the generated charges to the neighboring light-emitting unit, andmay include a known material.

The first light-emitting unit 151 may include a first emission layer151-EM, and the second light-emitting unit 152 may include a secondemission layer 152-EM. A maximum emission wavelength of light emitted bythe first light-emitting unit 151 may be different from a maximumemission wavelength of light emitted by the second light-emitting unit152. For example, mixed light of the light emitted by the firstlight-emitting unit 151 and the light emitted by the secondlight-emitting unit 152 may be white light, but embodiments of thepresent disclosure are not limited thereto.

The first light-emitting unit 151 may include a first intermediate layer131 that is disposed on a side closer to the first electrode 110,directly contacts the first emission layer 151-EM, and includes a firsthole transport material, and the second light-emitting unit 152 mayinclude a second intermediate layer 132 that is disposed on a sidecloser to the first electrode 110, directly contacts the second emissionlayer 152-EM, and includes a first hole transport material. The firsthole transport material included in the first intermediate layer 131 andthe first hole transport material included in the second intermediatelayer 132 may be identical to or different from each other. The firstlight-emitting unit 151 may further include a first electron transportregion 171 between the charge-generation layer 141 and the firstemission layer 151-EM.

The first emission layer 151-EM and the second emission layer 152-EM mayeach include a host and a dopant. The dopant is an organometalliccompound, provided that the dopant does not include iridium.

The first light-emitting unit 151 may satisfy a condition ofHOMO(h1)−HOMO(host)<0 eV, wherein HOMO(h1) indicates a HOMO energy level(eV) of the first hole transport material included in the firstintermediate layer 131, i) when the host of the first emission layer151-EM consists of a single host, the HOMO(host) indicates a HOMO energylevel (eV) of the single host and ii) when the host of the firstemission layer 151-EM is a mixture of two or more different hosts, theHOMO(host) indicates the highest energy level among HOMO energy levels(eV) of the two or more different hosts. The HOMO(h1) and HOMO(host) aremeasured by using a photoelectron spectrometer in an ambient atmosphere.

Also, the second light-emitting unit 152 may satisfy a condition ofHOMO(h1)−HOMO(host)<0 eV, wherein HOMO(h1) indicates a HOMO energy level(eV) of the first hole transport material included in the secondintermediate layer 132, i) when the host of the second emission layer152-EM consists of a single host, the HOMO(host) indicates a HOMO energylevel (eV) of the single host and ii) when the host of the secondemission layer 152-EM is a mixture of two or more different hosts, theHOMO(host) indicates the highest energy level among HOMO energy levels(eV) of the two or more different hosts. The HOMO(h1) and HOMO(host) aremeasured by using a photoelectron spectrometer in an ambient atmosphere.

As described above, since the organic light-emitting device 100satisfies the condition of HOMO(h1)−HOMO(host)<0 eV, holes moved to thefirst emission layer 151-EM and the second emission layer 152-EM may beeasily trapped into the first emission layer 151-EM and the secondemission layer 152-EM. Therefore, since hole injection into the firstemission layer 151-EM and the second emission layer 152-EM isfacilitated, reduction of a driving voltage, prevention of interfacialdegradation between the first intermediate layer 131 and the firstemission layer 151-EM, prevention of interfacial degradation between thesecond intermediate layer 132 and the second emission layer 152-EM,prevention of luminance reduction according to a driving time (longlifespan), and a high external quantum efficiency, and the like for theorganic light-emitting device 100 may be achieved.

The first electrode 110, the hole transport region 120, and the secondelectrode 190 in FIG. 3 may be understood by referring to thedescription provided in connection with the first electrode 11, the holetransport region 12, and the second electrode 19 in FIG. 1.

The first intermediate layer 131 and the second intermediate layer 132in FIG. 3 may be understood by referring to the description provided inconnection with the intermediate layer 13 in FIG. 1, and the firstemission layer 151-EM and the second emission layer 152-EM may beunderstood by referring to the description provided in connection withthe emission layer 15 in FIG. 1.

The electron transport region 170 and the first electron transportregion 171 in FIG. 3 may be understood by referring to the descriptionprovided in connection with the electron transport region 17 in FIG. 1.

The organic light-emitting device in which the first light-emitting unit151 and the second light-emitting unit 152 satisfy the condition ofHOMO(h1)−HOMO(host)<0 eV and the iridium-free organometallic compound isincluded as the dopant has been described with reference to FIG. 3, butvarious modifications may be made thereto. For example, one of the firstlight-emitting unit 151 and the second light-emitting unit 152 of theorganic light-emitting device in FIG. 3 may be replaced with a knownlight-emitting unit.

Description of FIG. 4

FIG. 4 is a schematic view of an organic light-emitting device 200according to an embodiment.

The organic light-emitting device 200 includes a first electrode 210, asecond electrode 290 facing the first electrode 210, and a firstemission layer 251 and a second emission layer 252 stacked between thefirst electrode 210 and the second electrode 290.

A maximum emission wavelength of light emitted by the first emissionlayer 251 may be different from a maximum emission wavelength of lightemitted by the second emission layer 252. For example, mixed light ofthe light emitted by the first emission layer 251 and the light emittedby the second emission layer 252 may be white light, but embodiments ofthe present disclosure are not limited thereto.

A first intermediate layer 231 that directly contacts the first emissionlayer 251 and includes a first hole transport material may be disposedbetween the first emission layer 251 and the first electrode 210, and asecond intermediate layer 232 that directly contacts the second emissionlayer 252 and includes a first hole transport material may be disposedbetween the second emission layer 252 and the first electrode 210.

A hole transport region 220 may be disposed between the firstintermediate layer 231 and the first electrode 210, and an electrontransport region 270 may be disposed between the second emission layer252 and the second electrode 290.

The first emission layer 251 and the second emission layer 252 may eachinclude a host and a dopant. The dopant is an organometallic compound,provided that the dopant does not include iridium.

The organic light-emitting device 200 may satisfy a condition ofHOMO(h1)−HOMO(host)<0 eV with respect to the first emission layer 251and the first intermediate layer 231, wherein HOMO(h1) indicates a HOMOenergy level (eV) of the first hole transport material included in thefirst intermediate layer 231, i) when the host included in the firstemission layer 251 consists of a single host, the HOMO(host) indicates aHOMO energy level (eV) of the single host and ii) when the host includedin the first emission layer 251 is a mixture of two or more differenthosts, the HOMO(host) indicates the highest energy level among HOMOenergy levels (eV) of the two or more different hosts. The HOMO(h1) andHOMO(host) are measured by using a photoelectron spectrometer in anambient atmosphere.

Also, the organic light-emitting device 200 may satisfy a condition ofHOMO(h1)−HOMO(host)<0 eV with respect to the second emission layer 252and the second intermediate layer 232, wherein HOMO(h1) indicates a HOMOenergy level (eV) of the first hole transport material included in thesecond intermediate layer 232, i) when the host included in the secondemission layer 252 consists of a single host, the HOMO(host) indicates aHOMO energy level (eV) of the single host and ii) when the host includedin the second emission layer 252 is a mixture of two or more differenthosts, the HOMO(host) indicates the highest energy level among HOMOenergy levels (eV) of the two or more different hosts. The HOMO(h1) andHOMO(host) are measured by using a photoelectron spectrometer in anambient atmosphere.

As described above, since the organic light-emitting device 200satisfies the condition of HOMO(h1)−HOMO(host)<0 eV, holes moved to thefirst emission layer 251 and the second emission layer 252 may be easilytrapped into the first emission layer 251 and the second emission layer252. Therefore, since hole injection into the first emission layer 251and the second emission layer 252 is facilitated, reduction of a drivingvoltage, prevention of interfacial degradation between the firstintermediate layer 231 and the first emission layer 251, prevention ofinterfacial degradation between the second intermediate layer 232 andthe second emission layer 252, prevention of luminance reductionaccording to a driving time (long lifespan), and a high external quantumefficiency, and the like for the organic light-emitting device 200 maybe achieved.

The first electrode 210, the hole transport region 220, and the secondelectrode 290 in FIG. 4 may be understood by referring to thedescription provided in connection with the first electrode 11, the holetransport region 12, and the second electrode 19 in FIG. 1.

The first intermediate layer 231 and the second intermediate layer 232in FIG. 4 may be understood by referring to the description provided inconnection with the intermediate layer 13 in FIG. 1, and the firstemission layer 251 and the second emission layer 252 may be understoodby referring to the description provided in connection with the emissionlayer 15 in FIG. 1.

The electron transport region 270 in FIG. 4 may be understood byreferring to the description provided in connection with the electrontransport region 17 in FIG. 1.

The organic light-emitting device in which a set of the first emissionlayer 251 and the first intermediate layer 231 and a set of the secondemission layer 252 and the second intermediate layer 232 satisfy thecondition of HOMO(h1)−HOMO(host)<0 eV and the iridium-freeorganometallic compound is included as the dopant has been describedwith reference to FIG. 4, but various modifications may be made thereto.

For example, any three of the first emission layer 251, the firstintermediate layer 231, the second emission layer 252, and the secondintermediate layer 232 may be replaced with known layers.

Description of Terms

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear orbranched saturated aliphatic hydrocarbon monovalent group having 1 to 60carbon atoms, and non-limiting examples thereof include a methyl group,an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and non-limiting examples thereof include a methoxy group, an ethoxygroup, and an isopropyloxy group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon double bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethenyl group, a propenyl group, and a butenyl group.The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalentgroup having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbongroup formed by including at least one carbon-carbon triple bond in themiddle or at the terminus of the C₂-C₆₀ alkyl group, and examplesthereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀alkynylene group” as used herein refers to a divalent group having thesame structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalentsaturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, andnon-limiting examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group” as used herein refers to adivalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to amonovalent saturated monocyclic group having at least one heteroatomselected from N, O, P, Si and S as a ring-forming atom and 1 to 10carbon atoms, and non-limiting examples thereof include atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to amonovalent monocyclic group that has 3 to 10 carbon atoms, at least onecarbon-carbon double bond in the ring thereof, and which has noaromaticity. Non-limiting examples thereof include a cyclopentenylgroup, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group” as used herein refers to a divalent group havingthe same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, P, Si, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one double bond in its ring. Examples of the C₁-C₁₀heterocycloalkenyl group are a 2,3-dihydrofuranyl group, and a2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup” as used herein refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent grouphaving a carbocyclic aromatic system having 6 to 60 carbon atoms, andthe term “C₆-C₆₀ arylene group” as used herein refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, anaphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenylgroup, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused toeach other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalentgroup having a heterocyclic aromatic system that has at least oneheteroatom selected from N, O, P, Si, and S as a ring-forming atom, and1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as usedherein refers to a divalent group having a heterocyclic aromatic systemthat has at least one heteroatom selected from N, O, P, and S as aring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples ofthe C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinylgroup, a pyrazinyl group, a pyridazinyl group, a triazinyl group, aquinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroarylgroup and the C₁-C₆₀ heteroarylene group each include two or more rings,the rings may be fused to each other.

The term “C₆-C₆₀ aryloxy group” as used herein indicates —OA₁₀₂ (whereinA₁₀₂ is the C₆-C₆₀ aryl group), a C₆-C₆₀ arylthio group as used hereinindicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group), and the term“C₇-C₆₀ arylalkyl group” as used herein indicates —A₁₀₄A₁₀₅ (whereinA₁₀₄ is the C₆-C₅₉ aryl group and A₁₀₅ is the C₁-C₅₃ alkyl group).

The term “C₁-C₆₀ heteroaryloxy group” as used herein refers to —OA₁₀₆(wherein A₁₀₆ is the C₁-C₆₀ heteroaryl group), and the term “C₁-C₆₀heteroarylthio group” as used herein indicates —SA₁₀₇ (wherein A₁₀₇ isthe C₁-C₆₀ heteroaryl group).

The term “C₂-C₆₀ heteroarylalkyl group” as used herein refers to—A₁₀₈A₁₀₉ (A₁₀₉ is a C₁-C₅₉ heteroaryl group, and A₁₀₈ is a C₁-C₅₈alkylene group).

The term “monovalent non-aromatic condensed polycyclic group” as usedherein refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed to each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. Examples of the monovalent non-aromatic condensed polycyclicgroup include a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group,” used herein, refers to a divalent grouphaving the same structure as the monovalent non-aromatic condensedpolycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 2 to 60carbon atoms) having two or more rings condensed to each other, aheteroatom selected from N, O, P, Si, and S, other than carbon atoms, asa ring-forming atom, and no aromaticity in its entire molecularstructure. Non-limiting examples of the monovalent non-aromaticcondensed heteropolycyclic group include a carbazolyl group. The term“divalent non-aromatic condensed heteropolycyclic group” as used hereinrefers to a divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group (or, C₅-C₃₀ carbocyclic group)” asused herein refers to a saturated or unsaturated cyclic group having, asa ring-forming atom, 5 to 60 carbon atoms (or, 5 to 30 carbon atoms)only. The C₅-C₆₀ carbocyclic group (or, C₅-C₃₀ carbocyclic group) may bea monocyclic group or a polycyclic group.

The term “C₁-C₆₀ heterocyclic group (or, C₁-C₃₀ heterocyclic group)” asused herein refers to a saturated or unsaturated cyclic group having, asa ring-forming atom, at least one heteroatom selected from N, O, Si, P,and S other than 1 to 60 carbon atoms (or, 1 to 30 carbon atoms). TheC₁-C₆₀ heterocyclic group (or, C₁-C₃₀ heterocyclic group) may be amonocyclic group or a polycyclic group.

At least one substituent of the substituted C₅-C₆₀ carbocyclic group(or, C₅-C₃₀ carbocyclic group), the substituted C₁-C₆₀ heterocyclicgroup (or, C₁-C₃₀ heterocyclic group), the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₇-C₆₀ arylalkyl group, the substituted C₁-C₆₀heteroaryl group, the substituted C₁-C₆₀ heteroaryloxy group, thesubstituted C₁-Coo heteroarylthio group, the substituted C₂-C₆₀heteroarylalkyl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazine group, a hydrazone group, a carboxylic acid group ora salt thereof, a sulfonic acid group or a salt thereof, a phosphoricacid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkyl group, a C₁-C₆₀ heteroarylgroup, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀ heteroarylthio group, aC₂-C₆₀ heteroarylalkyl group, a monovalent non-aromatic condensedpolycyclic group, a monovalent non-aromatic condensed heteropolycyclicgroup, —N(Q₁₁)(Q₁₂), —Si(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), and—P(═O)(Q₁₈)(Q₁₉);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂,—CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazine group, a hydrazone group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxygroup, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, aC₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀arylalkyl group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a C₁-C₆₀ heteroarylalkyl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂),—Si(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), and —P(═O)(Q₂₈)(Q₂₉); and

—N(Q₃₁)(Q₃₂), —Si(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), and —P(═O)(Q₃₈)(Q₃₉),and

Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinegroup, a hydrazone group, a carboxylic acid group or a salt thereof, asulfonic acid group or a salt thereof, a phosphoric acid group or a saltthereof, a C₁-C₆₀ alkyl group, a C₁-C₆₀ alkyl group substituted with atleast one selected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀aryl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with at least oneselected from deuterium, a C₁-C₆₀ alkyl group, and a C₆-C₆₀ aryl group,a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₇-C₆₀ arylalkylgroup, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxy group, a C₁-C₆₀heteroarylthio group, a C₂-C₆₀ heteroarylalkyl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group.

The terms “a biphenyl group, a terphenyl group, and a tetraphenyl group(or, a quaterphenyl group)” as used herein each refer to a monovalentgroup having two, three, or four phenyl groups linked via a single bond.

Hereinafter, a compound and an organic light-emitting device accordingto embodiments are described in detail with reference to SynthesisExample and Examples. However, the organic light-emitting device is notlimited thereto. The wording “B was used instead of A” used indescribing Synthesis Examples means that an amount of A used wasidentical to an amount of B used, in terms of a molar equivalent.

Examples Synthesis Example 1: Synthesis of Compound 3-170

Synthesis of Intermediate a (2-(3-Bromophenyl)-4-Phenylpyridine)

3 grams (g) (13 millimoles, mmol) of 2-bromo-4-phenylpyridine, 3.1 g(1.2 equivalents, equiv.) of (3-bromophenyl)boronic acid, 1.1 g (0.9mmol, 0.07 equiv.) of tetrakis(triphenylphosphine)palladium(0), and 3.4g (32 mmol, 3 equiv.) of sodium carbonate were mixed with 49 milliliters(mL) of a solvent in which tetrahydrofuran (THF) and distilled water(H₂O) were mixed at a volume ratio of 3:1, and then refluxed for 12hours. A reaction product obtained therefrom was cooled to roomtemperature, and a precipitate was filtered therefrom to obtain afiltrate. Then, the filtrate was washed by using ethyl acetate (EA)/H₂O,and purified by column chromatography (while increasing a rate of MC(methylene chloride)/Hex (hexane) to between 25% and 50%) to obtain 3.2g (yield: 80%) of Intermediate A. The obtained compound was identifiedby mass spectrometry and HPLC analysis.

HRMS (MALDI) calcd for C₁₇H₁₂BrN: m/z 309.0153, Found: 309.0155.

Synthesis of Intermediate B(4-phenyl-2-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine)

3.2 g (0.01 mmol) of Intermediate A and 3.9 g (0.015 mol, 1.5 equiv.) ofbispinacolatodiboron were added to a flask. 2.0 g (0.021 mol, 2 equiv.)of potassium acetate and 0.42 g (0.05 equiv.) of PdCl₂(dppf) were addedthereto, and 34 mL of toluene was added thereto. Then, the resultantmixture was refluxed at a temperature of 100° C. through the night. Areaction product obtained therefrom was cooled to room temperature, anda precipitate was filtered therefrom to obtain a filtrate. Then, thefiltrate was washed by using EA/H₂O, and purified by columnchromatography to obtain 2.4 g (yield: 65%) of Intermediate B. Theobtained compound was identified by mass spectrometry and HPLC analysis.

HRMS (MALDI) calcd for C₂₃H₂₄BNO₂: m/z 357.1900, Found: 357.1902.

Synthesis of Intermediate D(2,4-di-tert-butyl-6-(1-phenyl-4-(3-(4-phenylpyridin-2-yl)phenyl)-1H-benzo[d]imidazol-2-yl)phenol)

2.7 g (0.006 mol, 1 equiv.) of Intermediate C(2-(4-bromo-1-phenyl-1H-benzo[d]imidazol-2-yl)-4,6-di-tert-butylphenol),2.4 g (0.007 mol, 1.2 equiv.) of Intermediate B, 0.39 g (0.001 mol, 0.07equiv.) of tetrakis(triphenylphosphine)palladium(0), and 2.0 g (0.017mol, 3 equiv.) of potassium carbonate were mixed with 20 mL of a solventin which THF and distilled water (H₂O) were mixed at a volume ratio of3:1, and then refluxed for 12 hours. A reaction product obtainedtherefrom was cooled to room temperature, and a precipitate was filteredtherefrom to obtain a filtrate. Then, the filtrate was washed by usingEA/H₂O, and purified by column chromatography (while increasing a rateof EA/Hex to between 20% and 35%) to obtain 2.4 g (yield: 70%) ofIntermediate D. The obtained compound was identified by massspectrometry and HPLC analysis

HRMS (MALDI) calcd for C₄₄H₄₁BN₃O: m/z 627.3250, Found: 627.3253.

Synthesis of Compound 3-170

2.4 g (3.82 mmol) of Intermediate D and 1.9 g (4.6 mmol, 1.2 equiv.) ofK₂PtCl₄ were mixed with 55 mL of a solvent in which 50 mL of AcOH and 5mL of H₂O were mixed, and then refluxed for 16 hours. A reaction productobtained therefrom was cooled to room temperature, and a precipitate wasfiltered therefrom. The precipitate was dissolved again in MC and washedby using H₂O. The precipitate then was purified by column chromatography(MC 40%, EA 1%, Hex 59%) to obtain 1.2 g (purity: 99% or more) ofCompound 3-170 (actual synthesis yield: 70%). The obtained compound wasidentified by mass spectrometry and HPLC analysis.

HRMS (MALDI) calcd for C₄₄H₃₉N₃OPt: m/z 820.2741, Found: 820.2744.

Synthesis Example 2: Synthesis of Compound 1-8

Synthesis of Intermediate G

2.6 g (68%) of Intermediate G was synthesized in the same manner asIntermediate D in Synthesis Example 1, except that 2.5 g (0.006 mol) ofCompound E was used instead of Intermediate C, and 3.1 g (0.007 mol) ofCompound F was used instead of Intermediate B.

HRMS (MALDI) calcd for C₄₅H₄₃N₃O: m/z 641.3406, Found: 641.3408.

Synthesis of Compound 1-8

2.4 g (yield: 71%) of Compound 1-8 was synthesized in the same manner asCompound 3-170 in Synthesis Example 1, except that 2.6 g (4.05 mmol) ofIntermediate G was used instead of Intermediate D.

HRMS (MALDI) calcd for C₄₅H₄₁N₃OPt: m/z 834.2897, Found: 834.2896.

Evaluation Example 1

HOMO energy levels of the following Compounds were measured by using aphotoelectron spectrometer (manufactured by RIKEN KEIKI Co., Ltd.: AC3)in an ambient atmosphere, and results thereof are shown in Table 1below.

TABLE 1 Actual measurement value of HOMO energy level Compound (eV) HT1−5.35 HT3 −5.58 HT4 −5.65 HT5 −5.68 H-H1 −5.57 H-E1 −6.07 3-170 −5.431-8 −5.36 D-Ir −5.15

Comparative Example A

An ITO glass substrate was cut to a size of 50 mm×50 mm×0.5 mm(mm=millimeter), sonicated with acetone, isopropyl alcohol, and purewater, each for 15 minutes, and then cleaned by exposure to ultraviolet(UV) rays and ozone for 30 minutes.

Then, F6-TCNNQ was deposited on an ITO electrode (anode) of the ITOglass substrate to form a hole injection layer having a thickness of 100Angstroms (Å), HT1 was deposited on the hole injection layer to form afirst hole transport layer having a thickness of 1,260 Å, and F6-TCNNQand HT1 were co-deposited on the first hole transport layer at a weightratio of 5:95 to form a second hole transport layer having a thicknessof 100 Å, thereby forming a hole transport region.

HT1 was deposited on the hole transport region to form an intermediatelayer having a thickness of 300 Å.

Then, H-H1 (hole transport host) and H-E1 (electron transport host) (aweight ratio of the hole transport host to the electron transport hostwas 5:5) as a host and Compound 3-170 as a dopant were co-deposited onthe intermediate layer (a weight ratio of the host to the dopant was90:10) to form an emission layer having a thickness of 400 Å.

Then, Compound ET1 and LiQ were co-deposited on the emission layer at aweight ratio of 5:5 to form an electron transport layer having athickness of 360 Å, LiF was deposited on the electron transport layer toform an electron injection layer having a thickness of 5 Å, and Al wasvacuum-deposited on the electron injection layer to form a secondelectrode (cathode) having a thickness of 800 Å, thereby completing themanufacture of an organic light-emitting device having a structure ofITO/F6-TCNNQ (100 Å)/HT1 (1,260 Å)/HT1: F6-TCNNQ (5 wt %) (100 Å)/HT1(300 Å)/(H-H1+H-E1): Compound 3-170 (10 wt %) (400 Å)/ET1: LiQ (50 wt %)(360 Å)/LiF (5 Å)/Al (800 Å).

Comparative Example B and Examples 1 and 2

Organic light-emitting devices were manufactured in the same manner asin Comparative Example A, except that Compounds shown in Table 2 wereeach used instead of HT1 as the first hole transport material in formingan intermediate layer.

Evaluation Example 2

External quantum efficiency and lifespan (T₉₅) of the organiclight-emitting devices manufactured according to Comparative Examples Aand B and Examples 1 and 2 were evaluated, and evaluation resultsthereof are shown in Table 2 below. Also, a luminance-external quantumefficiency graph and a time-luminance graph of Comparative Examples Aand B and Examples 1 and 2 are shown in FIGS. 5 and 6, respectively. Theevaluation was performed by using a current-voltage meter (Keithley2400) and a luminance meter (Minolta Cs-1000A), and lifespan (T₉₅) (at8000 nit) indicates an amount of time (hr) that lapsed when luminancewas 95% of initial luminance (100%). The external quantum efficiency andthe lifespan (T₉₅) were measured at a luminance of 8,000 candelas persquare meter (cd/m²).

TABLE 2 First hole transport Hole transport HOMO of first Externalmaterial (actual host (actual Dopant (actual hole transport quantummeasurement measurement measurement material - HOMO efficiency Lifespanvalue of HOMO) value of HOMO) value of HOMO) of hole transport host (%)(hr) (T₉₅) Comparative HT1 H-H1 3-170 0.22 eV 17.03 150 Example A (−5.35eV) (−5.57 eV) (−5.43 eV) Comparative H-H1 H-H1 3-170 0 eV 23.67 400Example B (−5.57 eV) (−5.57 eV) (−5.43 eV) Example 1 HT3 H-H1 3-170−0.01 eV 24.80 500 (−5.58 eV) (−5.57 eV) (−5.43 eV) Example 2 HT4 H-H13-170 −0.08 eV 24.57 750 (−5.65 eV) (−5.57 eV) (−5.43 eV)

Referring to Table 2, it is confirmed that the organic light-emittingdevices of Examples 1 and 2 have excellent external quantum efficiencyand lifespan characteristics, as compared with those of the organiclight-emitting devices of Comparative Examples A and B.

Comparative Examples C and D

Organic light-emitting devices were manufactured in the same manner asin Comparative Example A, except that Compounds shown in Table 3 wereeach used instead of HT1 as the first hole transport material in formingan intermediate layer, and an Ir complex D-Ir was used instead ofCompound 3-170 as a dopant in forming an emission layer.

Comparative Example E and Example 3

Organic light-emitting devices were manufactured in the same manner asin Comparative Example A, except that Compounds shown in Table 3 wereeach used instead of HT1 as the first hole transport material in formingan intermediate layer, and Compound 1-8 was used instead of Compound3-170 as a dopant in forming an emission layer.

Evaluation Example 3

The external quantum efficiency and lifespan (T₉₅) of the organiclight-emitting devices manufactured according to Comparative Examples C,D, and E and Example 3 were evaluated, and evaluation results thereofare shown in Table 3 below. Also, a time-luminance graph of ComparativeExamples C and D is shown in FIG. 7, and a time-luminance graph ofComparative Example E and Example 3 is shown in FIG. 8. The evaluationwas performed by using a current-voltage meter (Keithley 2400) and aluminance meter (Minolta Cs-1000A), and the lifespan (T₉₅) (at 6000 nit)indicates an amount of time (hr) that lapsed when luminance was 95% ofinitial luminance (100%). The external quantum efficiency and thelifespan (T₉₅) were measured at a luminance of 6,000 cd/m².

TABLE 3 First hole transport Hole transport HOMO of first Externalmaterial (actual host (actual Dopant (actual hole transport quantummeasurement measurement measurement material - HOMO efficiency Lifespanvalue of HOMO) value of HOMO) value of HOMO) of hole transport host (%)(hr) (T₉₅) Comparative H-H1 H-H1 D-Ir 0 eV 17.2 800 Example C (−5.57 eV)(−5.57 eV) (−5.15 eV) Comparative HT5 H-H1 D-Ir −0.11 eV 17.6 580Example D (−5.68 eV) (−5.57 eV) (−5.15 eV) Comparative H-H1 H-H1 1-8 0eV 22.9 320 Example E (−5.57 eV) (−5.57 eV) (−5.36 eV) Example 3 HT5H-H1 1-8 −0.11 eV 23.33 400 (−5.68 eV) (−5.57 eV) (−5.36 eV)

Referring to Table 3, it is found that as to the cases where an Ircomplex D-Ir was used as a dopant, the lifespan of Comparative Example D(“HOMO of the first hole transport material−HOMO of hole transport host”was less than 0) was inferior to the lifespane of Comparative Example C(“HOMO of the first hole transport material−HOMO of the hole transporthost” was 0), but as to the cases where an iridium-free organometalliccompound was used as a dopant, Example 3 (“HOMO of the first holetransport material−HOMO of hole transport host” was less than 0) hasimproved external quantum efficiency and lifespan at the same time, ascompared with those of Comparative Example E (“HOMO of the first holetransport material−HOMO of the hole transport host” was 0).

The organic light-emitting device that satisfies certain parameters andincluding an iridium-free organometallic compound may have high externalquantum efficiency.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments.

While one or more embodiments have been described with reference to thefigures, it will be understood by those of ordinary skill in the artthat various changes in form and details may be made therein withoutdeparting from the spirit and scope of the present disclosure as definedby the following claims.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; and anorganic layer disposed between the first electrode and the secondelectrode, wherein the organic layer comprises an emission layer, and anintermediate layer disposed between the first electrode and the emissionlayer, the intermediate layer directly contacts the emission layer andcomprises a first hole transport material, the emission layer comprisesa host and a dopant, the dopant is an organometallic compound, providedthat the dopant does not comprise iridium, and the organiclight-emitting device satisfies a condition of HOMO(h1)−HOMO(host)<0electron volts, wherein HOMO(h1) indicates the highest occupiedmolecular orbital (HOMO) energy level (expressed in electron volts) ofthe first hole transport material, i) when the host consists of a singlehost, the HOMO(host) indicates a HOMO energy level (expressed inelectron volts) of the single host and ii) when the host is a mixture oftwo or more different hosts, the HOMO(host) indicates the highest energylevel among HOMO energy levels (expressed in electron volts) of the twoor more different hosts, and HOMO(h1) and HOMO(host) are measured byusing a photoelectron spectrometer in an ambient atmosphere.
 2. Theorganic light-emitting device of claim 1, wherein the organiclight-emitting device satisfies a condition of −0.4 electronvolts≤HOMO(h1)−HOMO(host)<0 electron volts.
 3. The organiclight-emitting device of claim 1, wherein the organic light-emittingdevice satisfies a condition of HOMO(dopant)−HOMO(host)<0.40 electronvolts, wherein HOMO(dopant) is a HOMO energy level (expressed inelectron volts) of the dopant included in the emission layer, andHOMO(dopant) is measured by using a photoelectron spectrometer in anambient atmosphere.
 4. The organic light-emitting device of claim 3,wherein the organic light-emitting device satisfies a condition of 0electron volts <HOMO(dopant)−HOMO(host)≤0.25 electron volts.
 5. Theorganic light-emitting device of claim 1, further comprising a holetransport region between the first electrode and the intermediate layer,wherein the hole transport region comprises a second hole transportmaterial, and the organic light-emitting device satisfies a condition ofHOMO(h1)−HOMO(h2)<0 electron volts, wherein HOMO(h2) is a HOMO energylevel of the second hole transport material, and HOMO(h2) is measured byusing a photoelectron spectrometer.
 6. The organic light-emitting deviceof claim 5, wherein the organic light-emitting device satisfies acondition of HOMO(h1)<HOMO(host)<HOMO(h2).
 7. The organic light-emittingdevice of claim 5, wherein the organic light-emitting device satisfies acondition of HOMO(h1)<HOMO(host)<HOMO(dopant)<HOMO(h2).
 8. The organiclight-emitting device of claim 1, wherein the dopant is anorganometallic compound comprising platinum (Pt), osmium (Os), titanium(Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium(Tm), rhodium (Rh), ruthenium (Ru), rhenium (Re), beryllium (Be),magnesium (Mg), aluminum (Al), calcium (Ca), manganese (Mn), cobalt(Co), copper (Cu), zinc (Zn), gallium (Ga), germanium (Ge), rhodium(Rh), palladium (Pd), silver (Ag), or gold (Au).
 9. The organiclight-emitting device of claim 1, wherein the dopant is anorganometallic compound comprising platinum (Pt) or palladium (Pd). 10.The organic light-emitting device of claim 1, wherein the dopantcomprises a metal M and an organic ligand, and the metal M and theorganic ligand form one, two, or three cyclometallated rings.
 11. Theorganic light-emitting device of claim 1, wherein the dopant comprises ametal M and a tetradentate organic ligand capable of forming three orfour cyclometallated rings with the metal M, the metal M comprisesplatinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf),europium (Eu), terbium (Tb), thulium (Tm), rhodium (Rh), ruthenium (Ru),rhenium (Re), beryllium (Be), magnesium (Mg), aluminum (Al), calcium(Ca), manganese (Mn), cobalt (Co), copper (Cu), zinc (Zn), gallium (Ga),germanium (Ge), rhodium (Rh), palladium (Pd), silver (Ag), or gold (Au),and the tetradentate organic ligand comprises a benzimidazole group anda pyridine group.
 12. The organic light-emitting device of claim 1,wherein the host comprises an electron transport host and a holetransport host, wherein the electron transport host comprises at leastone electron transport moiety, and the hole transport host comprises noelectron transport moiety, and HOMO(host) is the same as the HOMO energylevel of the hole transport host.
 13. The organic light-emitting deviceof claim 12, wherein the electron transport moiety is selected from acyano group, a π electron-depleted nitrogen-containing cyclic group, anda group represented by one of the following formulae:

wherein *, *′, and *″ in the formulae each indicate a binding site to aneighboring atom.
 14. The organic light-emitting device of claim 1,wherein the host comprises an electron transport host and a holetransport host, the electron transport host comprises at least one πelectron-depleted nitrogen-free cyclic group and at least one electrontransport moiety, and the hole transport host comprises at least one πelectron-depleted nitrogen-free cyclic group, and does not comprise anelectron transport moiety.
 15. The organic light-emitting device ofclaim 1, wherein the host comprises an electron transport host and ahole transport host, the electron transport host comprises atriphenylene group and a triazine group, and the hole transport hostcomprises a carbazole group.
 16. The organic light-emitting device ofclaim 5, wherein the first hole transport material and the second holetransport material are each independently selected from amine-basedcompounds.
 17. The organic light-emitting device of claim 1, wherein theintermediate layer does not comprise a p-dopant.
 18. The organiclight-emitting device of claim 5, wherein the hole transport regionfurther comprises a p-dopant.
 19. An organic light-emitting devicecomprising: a first electrode; a second electrode facing the firstelectrode; light-emitting units in the number of m, stacked between thefirst electrode and the second electrode and comprising at least oneemission layer; and charge-generation layers in the number of m−1,disposed between two neighboring light-emitting units selected from thelight-emitting units in the number of m and comprising an n-typecharge-generation layer and a p-type charge-generation layer, wherein mis an integer greater than or equal to 2, a maximum emission wavelengthof light emitted by at least one of the light-emitting units in thenumber of m is different from a maximum emission wavelength of lightemitted by at least one of the other light-emitting units, at least oneof the light-emitting units in the number of m comprises at least oneintermediate layer that is located at a side closer to the firstelectrode, directly contacts the emission layer, and comprises a firsthole transport material, the emission layer comprises a host and adopant, the dopant is an organometallic compound, provided that thedopant does not comprise iridium, and the organic light-emitting devicesatisfies a condition of HOMO(h1)−HOMO(host)<0 electron volts, whereinHOMO(h1) indicates a HOMO energy level (expressed in electron volts) ofthe first hole transport material, i) when the host consists of a singlehost, the HOMO(host) indicates a HOMO energy level (expressed inelectron volts) of the single host and ii) when the host is a mixture oftwo or more different hosts, the HOMO(host) indicates the highest energylevel among HOMO energy levels (expressed in electron volts) of the twoor more different hosts, and HOMO(h1) and HOMO(host) are measured byusing a photoelectron spectrometer in an ambient atmosphere.
 20. Anorganic light-emitting device comprising: a first electrode; a secondelectrode facing the first electrode; and emission layers in the numberof m, stacked between the first electrode and the second electrode,wherein m is an integer greater than or equal to 2, a maximum emissionwavelength of light emitted by at least one of the emission layers inthe number of m is different from a maximum emission wavelength of lightemitted by at least one of the other emission layers, at least oneintermediate layer that directly contacts at least one of the emissionlayers and comprises a first hole transport material is disposed betweenthe emission layers in the number of m and the first electrode, theemission layers each comprise a host and a dopant, the dopant is anorganometallic compound, provided that the dopant does not compriseiridium, the organic light-emitting device satisfies a condition ofHOMO(h1)−HOMO(host)<0 electron volts, wherein HOMO(h1) indicates a HOMOenergy level (expressed in electron volts) of the first hole transportmaterial, i) when the host consists of a single host, the HOMO(host)indicates a HOMO energy level (expressed in electron volts) of thesingle host and ii) when the host is a mixture of two or more differenthosts, the HOMO(host) indicates the highest energy level among HOMOenergy levels (expressed in electron volts) of the two or more differenthosts, and HOMO(h1) and HOMO(host) are measured by using a photoelectronspectrometer in an ambient atmosphere.